Dear Diary (Yamaguchi Tadashi x Reader)
by SimplySunney
Summary: Something odd is going on with Karasuno's pinch-server, and the team is determined to find out what. Their investigation ends up taking an unexpected turn when they come across the freckled boys diary...


Nishinoya and Tanaka heard them before they saw them. It was similar to a stampede—the first-year middle-blocker and setter toe-to-toe, running as if their lives absolutely depended on it. It was only a moment later that the libero realized one of them held what looked like a book in his hand.

"Oi, oi! Slow down!" Tanaka hollered as he stepped out of the way of the underclassmen who came to a speeding stop before them, huffing for air.

"I won!" Hinata puffed out.

"Bullshit!" Kageyama turned to the short red-head, fist raised and ready to argue before Nishinoya stepped between them.

"Nevermind that!" he interrupted. "What do you have, Shouyou?"

Hinata held the book out towards the second-year, looking both excited and guilty with the fidgeting grimace on his face. As Nishinoya took it from his grasp and opened it, the three all peeked over his shoulder and at the pages before them.

"It's…" Nishinoya started, rapidly flipping through the book.

"A diary!?" Hinata and Tanaka exclaimed in disbelief.

.

. .

 _. . .The Previous day_ . . .

"What's with Yamaguchi?" Karasuno's second-year wing-spiker, Tanaka, turned to ask the taller underclassman.

Tsukishima merely glowered at his teammate. "How should I know?"

The members exchanged glances with one another at the statement. If anyone would know what was up with Yamaguchi, it was Tsukishima. It had almost been a week now of Yamaguchi's odd behavior. He seemed to always be in a rush nowadays—his mind somewhere else. The Karasuno team brushed it off as nothing the first couple of times, but it kept happening. Day after day, practice would end and Yamaguchi would race to change back into his school uniform, bolting out with a rushed farewell and no explanation for his quick departure. The freckled boy's best friend seemed bothered that he was apparently as clueless as the rest of the team when it came to his unusual behavior.

"It's probably nothing," Sugawara assured Tsukishima with a reassuring pat on the back, immediately receiving an annoyed look in response.

"I wasn't even the one who asked," he grumbled.

"Maybe he's just having stomach problems," Hinata chimed in with knowing eyes. "Happens to me sometimes when I drink bad milk. Or when I'm really nervous."

"We know," Kageyama spoke with narrowed eyes directed at the short middle-blocker. Hinata defensively puffed up in response, looking ready to send out a heated retort.

"I don't think he's been rushing out just to take a crap," Tanaka immediately interjected before the team's oddball duo could break into another one of their renowned quarrels.

Meanwhile, the team's ace sat digging through his bag for his uniform. He paused and looked up with a thoughtful expression. "He _was_ kind of spaced out today, now that I think about it," Asahi spoke.

"Like Sugawara said, it's probably nothing. It's only been a few of days. We'll bring it up to him if he keeps acting strange," the team captain finalized while pulling on his jacket.

Suddenly a knowing chuckle sounded from the corner of the small changing room. All eyes turned to the source and were met with an arrogant looking libero, who sat with a sly smirk growing on his face.

"You guys really don't know?" he dramatically questioned with a raise of his brow. Tsukishima merely rolled his eyes in response.

"Why do you have to be so theatrical about it?" he irritably questioned, but the short libero paid no mine to the underclassman. Nishinoya stood up with an arrogant grin plastered onto his face—carefully eyeing them all with glowing eyes.

"Isn't it obvious with how he's been acting?" he continued. "Think about it."

All faces scrunched up in thought, excluding Tsukishima who simply continued to glare disdainfully at the second-year libero. When the silence simply extended, the solemn blonde finally let out an irritable sigh before speaking.

"He's always looking at the time, checking his phone whenever he can, and disappearing during lunch break," he quickly listed out with closed eyes. "He's definitely hiding something, but he even refuses to speak with me about it. He just gets flustered and changes the subject."

Wide-eyes stared at Tsukishima with certain awe—seeing the tall middle-blocker speak so excessively without a single damning remark was truly a sight to behold—but the libero had merely nodded in agreement while the blonde spoke.

"Exactly!" he exclaimed, pointing at the tall first-year with pleased eyes. Tsukishima's face scrunched up at the gesture. "If there's anything we can say for sure about Yamaguchi's behavior, it's that he's hiding something!"

"What's he hiding?" Hinata excitedly questioned.

"It can be anything!" Nishinoya replied with a sly grin. "But I do have a guess…" he suspensefully trailed off, but Sugawara cut in before the libero could finish.

"It's really none of our business either way," the third-year frowned.

"Of course it is!" Nishinoya immediately shot out, suddenly leaning towards the silver-haired setter with determined eyes. Sugawara flinched at the libero's abrupt motion. "We're a team! We shouldn't keep secrets from one another!"

"That's not necessarily true—" Asahi started to say, but the libero's boisterous voice overcame him.

"If there's something going on in one of our lives, then we should all know about it! Not keep it from each other!"

Daichi shook his head at the statement, "That's just ridiculous to expect—"

"Yeah!" Tanaka unknowingly interrupted from his excitement. "We're like brothers! Families don't keep secrets from each other!" The two second-years held their fists high with powerful resolve while Hinata admiringly stared with shining eyes. Tsukishima simply glowered at the noisy group; Sugawara and Asahi uneasily glancing between the shouting pair and the steadily growing irritated captain.

The remaining second-year members—Ennoshita, Kinoshita, and Narita—quickly made their escape during the fiasco. Kinoshita fighting laughter at the ridiculous spectacle and the other two members warily eyeing their captain as they made their way to the door.

"Good work today," Ennoshita muttered to Sugawara as they passed him, waving his goodbye at the upperclassmen. Sugawara shot them an apologetic smile as they departed.

"As I said before…" Daichi started again, but the excited red-head of the team unintentionally cut off the third-year by throwing his hands in the air and jumping towards the libero.

"Tell us, Noya-san!" Hinata practically begged. "Why do you think Yamaguchi is acting so—"

"OI!" Daichi suddenly barked at the underclassmen—terrified eyes jumped to the glooming wing-spiker. "We aren't going to nose into Yamaguchi's business, and that's that!" he bellowed at the now cowering members.

Sugawara sighed while shaking his head—Tsukishima rolling his eyes, and Asahi looking uncomfortable from the confrontation.

"Yes, sir…" the previously energetic group glumly answered.

After the encounter, the Karasuno members finished changing and gathered their belongings before walking out to the school's front gate. The third-years said their goodbyes to the underclassmen and headed off in their separate direction—Daichi yet again reminding them to leave Yamaguchi alone for the time being.

After they were gone, the first-years began to make their leave as well before the libero quickly caught their attention.

"Tsukishima!" he called out to the tall middle-blocker. The blonde paused mid-step and turned to the upperclassmen with a raise of his brow. Hinata, Kageyama, and Tanaka stopped as well, curious to see what the second-year had to say.

After what felt like too long of a silence, the sully blonde impatiently shifted on his feet. "What?" he asked.

"I know it bothers you that Yamaguchi is hiding something," the libero finally started. Tsukishima's brow twitched with annoyance in response. "Right now it's only a hunch, but I'll find out for sure what he's hiding!"

Tsukishima simply stared at the short second-year before turning to walk again, pulling his headphones over his head. "Do whatever you want," he spoke indifferently.

After the tall middle-blocker disappeared from their sight, Nishinoya turned to his teammates with a fidgeting expression. "Tsukishima annoys the hell out of me…but I'm really curious about Yamaguchi too."

The three members nodded their heads in agreement.

"And seeing Tsukishima without Yamaguchi next to him is honestly just weird."

Again, nods of agreement.

"So what should we do?" Tanaka asked, beginning to walk ahead with Nishinoya beside him and the two first-years following suit.

The libero grinned deviously at this. "We have to investigate."

"How are we going to do that?" Hinata curiously questioned. Nishinoya stopped in his tracks and turned to exaggeratedly point at the middle-blocker and setter.

"You guys need to find clues!" When the libero was met with blank stares, he continued, "During the lunch break tomorrow, go to his class and look through his things while he isn't in the room. Tsukishima said that he hasn't been eating there lately anyway."

Hinata looked uncertain. "But Daichi said—"

"Daichi won't find out about this!" Nishinoya quickly interrupted.

Hinata stared at him uneasily with furrowed brows. "…But you said that teammates don't keep secrets from each other, so—"

"This is different!" the libero cut the red-head off yet again with a wave of his hand. "Don't think too much about it, Shouyou. You want to help out Yamaguchi, right?"

The small decoy seemed flustered, but nodded his head nonetheless.

"I could tell that Yamaguchi wasn't practicing as seriously," Kageyama suddenly spoke. "Tsukishima may start slacking off too, unless we figure out what's wrong. Otherwise I wouldn't really care what they did," he finished matter-of-factly.

Tanaka snorted at this. "It's always the same with you," he stated with a shake of his head.

Not understanding what the upperclassman meant by this, Kageyama sent him a confused look, but Nishinoya interrupted by enthusiastically patting the two first-year's backs. A sly grin began to grow on his face.

"Meet us in front of the gymnasium during lunch," the libero looked expectantly at them until they nodded in reply. He then shot them a final thumbs up. "Good luck you two!"

With that, the four said their final goodbyes and headed their separate ways home—Tanaka and Nishinoya leaving together while Hinata scurried after Kageyama…

. . .

. .  
.

. . . _Present day_. . .

Four pairs of eager eyes tentatively glanced between one another before looking back down at the book before them.

Finally, Nishinoya audibly gulped and began to read. "It says—"

"What are you guys all doing out here?"

The four members jumped and the libero swiftly hid the book behind his back, all held forced smiles on their faces. Sugawara had appeared from the dressing room wearing his practice uniform. His eyes narrowed suspiciously at the underclassmen.

"What are you hiding?" he asked.

"S-Sugawara-san!" Hinata squeaked out. "What are you doing here?"

The third-year raised a brow at them, "I sometimes practice during lunchbreak."

"Well…We decided to practice too!" Tanaka quickly claimed. The look Sugawara had made it obvious to all of them that they weren't fooling the setter for a moment.

"Listen…" he slowly started while tentatively approaching the nervous group. "You can tell me what you're hiding or…" he paused before flashing a cunning grin at them, "Or should I tell Daichi about this?"

Their faces immediately fell.

"N-No!" Hinata stuttered out, feverously flailing his hands out before him. "That's not necessary!"

"Don't tell Daichi, Suga-san!" Tanaka practically pleaded.

Sugawara simply held his hand out to the underclassmen with an expectant smile. Nishinoya slowly moved the book from behind him and into the upperclassmen's hand—the only thing that they could all think at the moment was how Sugawara could be just as terrifying as their captain (if not more so).

The silver-haired setter eyed the book in his hand expectedly before opening it and flipping through the pages.

"A diary?" he curiously inquired. A minute barely passed before his eyes widened in realization. He quickly turned to his teammates who all immediately looked every which way in order to avoid his accusing stare. "This is Yamaguchi's, isn't it?" he asked.

There was a pause. Soon, all heads nodded in unison and Sugawara let out a disgruntled sigh.

"I didn't think you guys would go as far as to snoop through his belongings," he groaned to himself with a disappointed shake of his head.

"I-I didn't know it was a diary!" Hinata quickly pleaded, face written with anxiety and guilt. "I just grabbed the first thing I saw!"

"So you didn't read it?" the third-year inquired.

"No!" they all answered in unison.

"Good, you guys should know better!" Sugawara scolded the group, receiving dropping looks in response. Then there was a pause of silence and their dejected expressions were replaced with ones of confusion.

"Suga-san?" Tanaka prompted.

The silver-haired setter's face grimaced and his hold on the book tightened. "I say that, but honestly I'm curious too…"

The member's eyes lit with their previous excitement at this.

"So…" Nishinoya started hesitantly. "Are you going to look at it?"

Sugawara's face contorted with mixed emotions, but he finally let out an aggravated breath of air and eyed the underclassmen expectantly. "This stays between us!" he ordered. The four Karasuno members nodded their heads vigorously to show their agreement.

"Alright…" the third-year started again, holding the book in front of him expectantly as the second and first-years gathered around him. Sugawara slowly opened the book and flipped until they fell upon the latest entry. All eyes eagerly stared at the passage before them…

Yamaguchi slowly blinked as he blankly stared into his school bag. After a brief moment of silence, he rummaged through it again. Then again, and again, and once more after that.

 _Crap._

His eyes jumped back to his desk and he desperately searched all around it—going through the pocketed area and even looking beneath it.

"Oh, Yamaguchi!"

The freckled boy simply glanced towards the classmate that called his name, more preoccupied with his search.

"Your friend's came by and said they needed to borrow some notes from you, if that's what you're looking for."

The pinch-server froze at this. "Do you remember who came by?" he urgently asked his classmate who seemed confused by Yamaguchi's flustered state.

"Um…Some shorty and a scary looking guy," his classmate tentatively answered.

Yamaguchi shot up and swiftly made his way to the class entrance. "Do you know which way they went?"

"I think towards the back, but I'm not really sure—"

The Karasuno member had already taken off before his classmate could finish his statement, leaving the boy confused from the encounter.

If Yamaguchi had to guess where those two headed off to he would bet the club room or somewhere by it. But what he couldn't figure out was why Hinata and Kageyama stole his journal to begin with.

His breath grew ragged as he raced through the familiar surroundings that were now just a blur that lead towards the Karasuno gymnasium. He could only hope his classmate was correct in leading him in the right direction, otherwise his teammates could be anywhere. Back at one of their classrooms, in the lunchrooms, in one of the courtyards…

He furiously shook his head as he made a turn down another corridor. He didn't want to think about it—he simply focused on one thing and that was making sure he found them before they read through his journal. There were countless of things in there that were meant for nobodies eyes but his own—Yamaguchi couldn't even comprehend the devastating embarrassment that would come along with them reading it.

But, more than anything, he hoped they at least didn't see his latest entries…Because that was something he had no intentions of sharing with anyone anytime soon. In fact, he's been purposely avoiding the subject all together—even with Tsukishima. He just didn't know how to bring it up…And he actually kind of liked the fact that it was secret.

The gymnasium finally came into sight and Yamaguchi felt as if his heart was jumping up his throat at what he saw before him. Huddled together with his journal in hand stood not only the two oddball idiots, but even Tanaka, Nishinoya, and (much to his surprise) the third-year setter, Sugawara.

He didn't even have to announce his arrival, for the five faces simultaneously looked up at him as they heard his charging approach. It didn't take a genius to understand what their dazed, flushed faces meant.

They had read it. He was too late.

His pace slowed to a jog at the realization and he attempted to control his labored breathing as he carefully watched his teammates before him. A pregnant pause surrounded the group as they simply stared at one another—assessing gazes looking unsure as to what to say and nobody willing to be the one to break the silence. It was a familiar yet unexpected voice that finally cut in.

"Tadashi-kun…"

All eyes turned towards the source, Yamaguchi gaping at the sight. His best friend came approaching with you walking beside him—Tsukishima looking curiously between the standoff of his teammates and you sending Yamaguchi a wary look.

"(y/n)-chan! Tsukki!" he finally let out in obvious surprise. "What are you two doing together?"

"I found out what you've been hiding," Tsukishima spoke nonchalantly. "And I don't really understand why you went through such lengths to keep the fact that you had a girlfriend from us."

"I wasn't…I mean, I…" Yamaguchi stuttered out, not knowing how to respond to his friend.

"You don't have to explain yourself," Tsukishima interjected. "She already filled me in with everything anyway. It makes sense that you two would want to spend more time together now that you're going out. Just don't be so secretive anymore."

"Right…" Yamaguchi started while sending you a questioning look.

"Erm, he's right, Tadashi!" you chimed in. "I was being selfish wanting to see you so often, but things will be easier now that your team knows." She turned to bow towards the still-flustered group, "Sorry for the trouble."

This seemed to snap the five out of whatever spell they were in. They shot up straight and let out sheepish laughs.

"Oh, it was no trouble," Tanaka started.

"Yeah, no need to apologize," Nishinoya awkwardly laughed before exchanging wary glances with the wing-spiker.

Kageyama and Hinata merely stood frigid with red faces and grimacing mouths, and Sugawara shot them a warning glance before approaching Yamaguchi. He uncomfortably rubbed at the back of his head while holding the journal out towards the freckled-boy. "Here's your…uh, notes!" he forcibly grinned. "Sorry for…Um, the trouble…"

"Thanks…" Yamaguchi muttered out, not willing to look the upperclassmen in the eyes due to his mortification.

"Well," Sugawara cleared his throat and looked between the pinch-server and the group behind him. "I should get to practicing now before lunchbreak is over." As he turned to walk towards the gym he sent you and wave. "Nice to meet you, (y/n)-chan!" You nodded in response and shot him a smile.

"Yeah, we should get going too, right guys?" Nishinoya spoke while sending a look to three members behind him. They all nodded in response.

"Let's hurry and eat before classes start again," Tanaka agreed, pushing along his underclassmen who still seemed too rattled to speak.

As they passed by Yamaguchi, the libero patted on his shoulder and whispered, "Good for you man."

Tanaka, grinning embarrassingly, added, "Our pinch-server's full of surprises!"

"D-diary's are cool!" Hinata randomly exclaimed in a hushed tone.

Yamaguchi visibly tensed at their comments and sent them a disbelieving look. "It's a journal not a—Forget it. Just go!" he desperately begged. They sent him apologetic grins and scurried away, leaving behind a flushed Yamaguchi.

The freckled boy then hesitantly turned to the remaining pair standing before them, the tall middle-blocker looking confused and you concerned.

"What was all that about?" Tsukishima asked with a raised brow.

"N-nothing," Yamaguchi spluttered out. "You know how they can be…" he finished uncertainly, attempting to meet the blonde's gaze without looking too suspicious.

His answer seemed to appease his friend enough, or perhaps he simply didn't care to inquire further.

"You're right about that," the tall first-year snorted. "I'm going to head back to class," he finally stated before walking away and sending them a brief wave of goodbye.

"I'll meet you there later!" Yamaguchi called after him.

After the blonde disappeared from sight, Yamaguchi turned towards you and let out a breath he wasn't aware that he had been holding. You closed the distance between the two of you and took his hands into your own.

"You okay?" you gently inquired.

He simply sighed and touched his forehead to yours, staring at you with kind yet humorful eyes. "Remind me to burn this thing later," he quietly joked.

You laughed at this, sending him a loving grin before moving to gently press your lips onto his. He wrapped his arms around you and moved into the kiss, thankful for this moment of solitude and peace after the previous chaos that had ensued.

You both finally pulled away and you send him a teasing glance. "Maybe just not bring it with you to school next time?" you quipped.

He visibly flushed at this and sent you a sheepish grin, "Duly noted."


End file.
